Branch prediction is a technique used in computer architecture to improve the flow of instruction execution by guessing thoe outcome of a branch (such as an if- else decision) before is known for sure. This helps in reducing delays caused by waiting for thee actual branch decision, thus rescening procesor pertency.

Types of Branch Prediction

There are seteral methods of branch prediction, each with different levels of completity and preciacy. Thee mogt common type include de static prediction and dynamic prediction.

Static vs. Dynamic Prediction

Static prediction relies on figed rules, such as always predicting that a branch wil be taken or not taken. Dynamic prediction uses hardware histority to make more informed guesses based on patt behavor of branches.

Practical Example of Dynamic Prediction

Consider a 2-bit saturating counter user for dynamic branch prediction. Thee counter can have four states: 00, 01, 10, 11. States 00 and 01 predict condition; not take in accussion;, while 10 and 11 predict condict; take n condition;. Thee counter updates based on actual branch outcomes.

If the counter is at 10 and the branch is taken, it moves to 11. If the branch is not taken, it moves to 01. This systemem helps improve prediction preciacy over time.

Calculating Prediction Accuracy

Prediction precinacy can be measured by thee predicage of correct guesses over total predictions. For exampla, if out of 100 branches, 90 are predicted correctly, thee preciacy is 90%.

  • Opravné předpovědi: 90
  • Total předpovědi: 100
  • Accuracy = (Correct / Total) × 100 = 90%